''Acokanthera oppositifolia'', the poison arrow tree, is a

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

used as the source of an arrow poison and to coat

caltrop A caltrop (also known as caltrap, galtrop, cheval trap, galthrap, galtrap, calthrop, jackrock or crow's foot''Battle of Alesia'' (Caesar's conquest of Gaul in 52 BC), Battlefield Detectives program, (2006), rebroadcast: 2008-09-08 on History C ...

s made from the sharp fruits of the puncture vine (''

Tribulus terrestris ''Tribulus terrestris'' is an annual plant in the caltrop family (Zygophyllaceae) widely distributed around the world. It is adapted to thrive in dry climate locations in which few other plants can survive. It is native to warm temperate and t ...

''). All plants of the genus '' Acokanthera'' contain toxic

cardiac glycoside Cardiac glycosides are a class of organic compounds that increase the output force of the heart and decrease its rate of contractions by inhibiting the cellular sodium-potassium ATPase pump. Their beneficial medical uses include treatments for ...

s strong enough to cause death. ''Acokanthera oppositifolia'' is widespread in southern and central

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

from

Cape Province The Province of the Cape of Good Hope (), commonly referred to as the Cape Province () and colloquially as The Cape (), was a province in the Union of South Africa and subsequently the Republic of South Africa. It encompassed the old Cape Co ...

north to The Democratic Republic of the Congo +

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

. '' Acokanthera schimperi'' is employed for the same purpose. Unlike all other parts of the plant, the ripe fruit is sweet and edible. Unripe fruit are still poisonous, so only really ripe fruit are eaten.

References

oppositifolia Plants described in 1792 Flora of Africa Fruits originating in Africa {{Apocynaceae-stub